This project intends to characterize fragments of human and rat serum albumins obtained by mild proteolytic digestion as well as by cleavage with cyanogen bromide. Studies of rat albumin will extend to its mode of biosynthesis and formation of disulfide bonding patterns. BIBLIOGRAPHIC REFERENCES: Peters, T., Jr. Cellular Protein Transport. In Albumin and Abnormal Protein Biosynthesis. M.A. Rothschild, M. Oratz, and S. S. Schreiber, eds., Pergamon Press, pp. 111-136 (1975). Feldhoff, R. C., Reed, R.G., and Peters, T., Jr. Structural features and ligand-binding properties of two halves of bovine albumin. Fed. Proc., Fed. Am. Soc. Exp. Biol. 34 (3), 591 (1975).